This application is based on applications Nos. H9-060911, H09-060914, and H9-060916 filed in Japan, the content of which is hereby incorporated by reference.
1. Field of the Invention
The present invention relates to an electronic still camera, and more specifically, to an electronic still camera having a function to prevent the right moment to take a photo from being missed.
2. Description of the Prior Art
In order to prevent the right moment to take a photo (hereinafter, this moment will be referred to as xe2x80x9cshutter chancexe2x80x9d) from being missed, an electronic still camera has been proposed which has a mode in which a plurality of images taken over a period spanning before and after the release operation is performed are recorded (hereinafter, this mode will be referred to as xe2x80x9cshutter chance modexe2x80x9d). In the camera having this mode, an internal memory is provided for temporarily storing images therein and an operation as described below has conventionally been performed.
When placed in the shutter chance mode, the camera starts photographing and storage of taken images in the internal memory irrespective of whether the user of the camera performs the release operation or not. After the start of the storage, after a predetermined number of images have been stored, the oldest image is replaced by the latest image one after another. The camera continues the photographing and the storage until a predetermined number of images have been taken after the release operation is performed. Then, the camera reads out the images stored in the internal memory and records them onto a recording medium such as a memory card. As the recording medium, that of an external device such as a personal computer connected to the camera is sometimes employed.
By thus recording the images taken over a period spanning before and after the release operation, an image taken at a substantially optimum moment is included in images taken before the release operation when the release operation by the user is late for the shutter chance, and is included in images taken after the release operation when the release operation is performed too early. As a result, the possibility is greatly reduced that the shutter chance is missed.
Memory cards are widely used as a standard recording medium for electronic still cameras; they are removable, and come in various recording capacities. However, at present, even memory cards having largest capacities available can store several tens of images at most. On the other hand, recording media that are used as external devices for personal computers and the like have far larger capacities than memory cards, and therefore they can store a huge number of images. If one of such external devices is connected to a camera, there will be practically no limit in terms of recording capacity, and thus it will be possible to use the shutter chance mode frequently. Unnecessary images can be erased readily later.
However, in conventional cameras, the number of images that can be shot and stored in the shutter chance mode is fixed regardless of the recording medium used. As a result, when the number of images that can be stored is set according to the capacity of a large-capacity recording medium, only a limited number of scenes can be stored in a memory card, whereas, when the number is determined according to the capacity of the memory card, it is not possible to make the most of the capacity of the large-capacity recording medium.
Moreover, since all the images stored in the internal memory in the shutter chance mode are recorded onto the recording medium, unnecessary images as well as necessary images are stored in the recording medium. For this reason, the recording capacity of the recording medium is wastefully used, so that the number of scenes that can be recorded is small. While the use of a large-capacity recording medium enables photographing of many scenes, this does not provide essential avoidance of waste of the recording capacity.
Since recording media for electronic still cameras are rewritable, it is a way of avoiding the waste of recording capacity to reproduce all of the recorded images when all the recording capacity of the recording medium has been used, determine the necessity of each image and erase the unnecessary images. However, according to this method, when all the recording capacity has been used after the erasure of the unnecessary images, it is necessitated to determine the necessity of all the images including the images that were not erased in the previous determination, so that the determination is performed a plurality of times for the same images. This is inconvenient.
In conventional cameras, the shutter chance mode simply repeats shooting at equal time intervals, and therefore, in cases where the object is moving quickly, there is, even in the shutter chance mode, a possibility that the best shutter chance is missed. Some cameras are provided with different modes such as a xe2x80x9cnormal modexe2x80x9d for shooting a stationary or slowly moving object and a xe2x80x9csports modexe2x80x9d for shooting a quickly moving object so that an appropriate mode can be selected at least for single-shot shooting. Even in such cameras, however, no consideration is given, in the shutter chance mode, to the speed of the object""s motion.
An object of the present invention is to provide an electronic still camera that, even in the shutter chance mode, can store a number of scenes in a recording medium having a relatively small capacity and can make the most of a recording medium having a relatively large capacity.
Another object of the present invention is to provide an electronic still camera wherein, of the images taken in the shutter chance mode, only necessary images are recorded onto a recording medium.
Still another object of the present invention is to provide an electronic still camera that can shoot even a quickly moving object surely without missing a shutter chance.
To achieve the above object, according to one aspect of the present invention, an electronic still camera is provided with an imaging apparatus for photographing a subject and generating image data of the subject; an operation member for providing a direction to start photographing; a first memory for storing therein image data of an image taken by the imaging apparatus; a selector for selecting any one of image data of a plurality of frames stored in the first memory; a second memory for storing therein image data of an image frame selected by the selector; and a controller for executing a pre-photographing control in which prior to the direction to start photographing provided by the operation member, the imaging apparatus is caused to photograph the subject and image data are stored in the first memory, and a post-photographing control in which in response to the direction to start photographing provided by the operation member, the imaging apparatus is caused to photograph the subject and image data are stored in the first memory. This electronic still camera is so designed that the selector selects any one of images of a plurality of frames taken through the pre-photographing control and the post-photographing control executed by the controller.
According to another aspect of the present invention, an electronic still camera is provided with an imaging apparatus for photographing a subject and generating image data of the subject; an operation member for providing a direction to start photographing; a memory for storing therein image data of an image taken by the imaging apparatus; and a controller for executing a pre-photographing control in which prior to the direction to start photographing provided by the operation member, the imaging apparatus is caused to repeatedly photograph the subject in a predetermined photographic cycle and image data are stored in the memory, and a post-photographing control in which in response to the direction to start photographing provided by the operation member, the imaging apparatus is caused to photograph the subject and image data are stored. This electronic still camera is designed to be capable of photographing in a plurality of photographic modes, and is so designed that the cycle is set in accordance with a selected photographic mode.
According to another aspect of the present invention, an electronic still camera is provided with an imaging apparatus for photographing a subject and generating image data of the subject; an operation member for providing a direction to start photographing; a memory for storing therein image data of an image taken by the imaging apparatus; and a controller for causing the imaging apparatus to repeatedly perform photographing in a predetermined cycle over a predetermined photographic period spanning before and after the direction to start photographing is provided by the operation member. This electronic still camera is designed to be capable of photographing in a plurality of photographic modes, and is so designed that the cycle is set in accordance with a selected photographic mode.
According to another aspect of the present invention, an electronic still camera is provided with an imaging apparatus for photographing a subject and generating image data of the subject; an operation member for providing a direction to start photographing; a memory for storing therein image data of an image taken by the imaging apparatus; and a controller for executing a pre-photographing control in which prior to the direction to start photographing provided by the operation member, the imaging apparatus is caused to repeatedly photograph the subject and image data of a predetermined number of frames are stored in the memory, and a post-photographing control in which in response to the direction to start photographing provided by the operation member, the imaging apparatus is caused to photograph the subject and image data are stored. This electronic still camera is designed to be capable of photographing in a plurality of photographic modes, and is so designed that the predetermined number is set in accordance with a selected photographic mode.
According to a further aspect of the present invention, an electronic still camera is provided with an imaging apparatus for photographing a subject and generating image data of the subject; an operation member for providing a direction to start photographing; a memory for storing therein image data of an image taken by the imaging apparatus; and a controller for causing the imaging apparatus to repeatedly perform photographing over a predetermined photographing period spanning before and after the direction to start photographing is provided by the operation member, the controller storing image data of a predetermined number of frames in the memory. This electronic still camera is designed to be capable of photographing in a plurality of photographic modes, and is so designed that the predetermined number is set in accordance with a selected photographic mode.